Mechanism design software - options?

I'm about to start a new series of medical design projectsthat will involve designing new mechanisms for folding. In the pastI've done these with SolidWorks and the sketcher, but some of theseare a bit complex and I'm really after a goal seek type ofsolution.

I've come across an application called Graphicalc before but neverused it. Not helped by the fact that it is not available in demoform to test. (www.inventbetter.com)

Has anyone here ever used it? If so is it any good? If not why not?Are there other alternatives? Are there any SolidWorks basedsolutions (aside from experimenting with the sketcher?).SolidworksGeneral